the damned "of" ... it always confuses me
Don't ask me for a grammatical analysis, please. I can't.
-robbed of: The gangsters robbed him of his watch and let him go. He told his colleagues that his watch was robbed of last night.
Here, "of" means removal or deprival (see "A New English-Chinese Dictionary" ed. Lu Gusun et al). Similar usage:
-cure sb. of sth.: I hope the new therapy would cure him of the chronic disease. I am surprised to hear that his chronic disease was cured of (so quickly by the new therapy).
-deprive sb. of sth.: The court also deprived him of the rights to appeal. His rights to appeal was deprived of (by the court).